seeley



Patented Dec. 23, 1919.

STAES 'E BEECH JAMES E. SEELEY, OF LOS ANGELES-CALIFORNIA; AIDA` SEELEY ADMINISTRATRIX OF SAID JAMES SEELEY, DECASED.

METHOD FOR MAKING LEAD PIGMENT.

Specification of Letters Patent.

Patented Dec. 23, 1919.

Application led February 5, 1917, Serial No. 146,645. Renewed October 6, 1919. Serial No. 328,931.

To all whom t may concern:

Be it known that I, JAMES E. SEELEY, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Method for Making Lead Pigment, of which the following is a specification.

This invention relates to a production of lead pigment, and the main object of the invention is to provide for making such pigment of a white colorand of high quality at a minimum of expense.

The making of white lead by the ordinary process now in Vuse Ais a slow and expensive operation. Attempts have been made to produce white .lead -in a more rapid and economical manner by the direct action of air. and water on the lead aided by mechanical agitation. As heretofore produced however, such a process has not produced a satisfactory quality of white lead, for the reason that the product was generally grayish or discolored, whereas the trade a pure white article.

An important object of the present invention is to provide for the production of a lead pigment which is pure white andis of extreme fineness and suitable quality for use as a pigment.

My process consists essentially in subjecting lead while agitated in the presence of the water to the action of ozonized air in such manner that the oxidization of the lead is greatly accelerated as compared with ordinary air oxidation. ln order to promote oxid ation, it is desirable to reduce the lead to a state of fairly fine subdivision, and. my invention further includes, as a step in the process, a special mode of operation for producing such subdivision. My invention also preferably comprises supplying carbon dioxid along with the ozonized air, so as to improve the quality of the product.

The accompanying drawings illustrate apparatus suitable for carrying out my invention and referring thereto:

Figure l is a vertical section of the apparatus for converting the finely divided metallic lead into leadj pigment.

Fig. 2 is a vertical section of the apparatus for reducing the metallic lead to a finely divided condition.

requires an ozonizer 1, al plurality of reaction cells or tanks 2, 3, 4, settling tanks 5 and 6 and suitable pipe connections for conductinglthe ozonized air to said cells and for conducting the liquid as hereinafter set forth.

The ozonizer l may be of any suitable construction, comprising, for example a tube 7 of insulating material, provided'with inlet and outlet means 8 and 9 for passing air therethrough, with an internal electrode l0 extending axially in said tube and with an external electrode 11 surrounding said tube, said electrodes l0 and ll being connected by wires l2 `and 13 to the high tension winding toa step-up transformer 14, whose low tension winding is connected to an alternating supply circuit indicated` at 17 and 13. The outlet pipe 9 for the ozonizer leads to a pump` or blower 20,.having an outlet pipe 2l connected by branch pipes 22,23, and 24, provided withvalves 26, `7, and 28, to the lower ends of the respective cells 2, 3 and 4. Each of these cells may consist of a vertical tubular receptacle or tank, which may be open at its upper end for escape of air therefrom. An overflow pipe-30 leads from the upper part of cell 2 to the `lower part of cell `3, and an overflow pipe 31 leads from the upper part of cell 3 to the lower part of cell 4. An over-flow pipe33 leads from the upper part of cell 4 to branch pipes 34 and 35, having valves 36 and 37 which discharge into settling tanks and 6 respectively. Said settling tanks are provided with pipes 38 and 39 having valves 40 and 41 respectively for drawing off the settled material from said tanks. Decanting pipes 42 and 43 extend from the tanks 5 and 6 respectively to the pipe 44 leading to the pump 45 whose outlet pipedischarges `through a valve 46 into a reservoir or tank 47. Said reservoir has an outlet 48 provided with a valve 49 `and discharging intov the first reaction cell or tank. 2.

The apparatus for reducing the lead to finely divided condition may be constructed as show-nin Fig. 2, comprising for example, a meltingpot 50` adapted to be heated bya suitable furnace 5l and having an outletr pipper 52provided with avalve 53 and adapted to'discharge the liquid lead into a body of water or other liquid in tank 54, Said tank may be provided with suitable means for supplying liquid thereto and with means 55 for drawing liquid therefrom when required.

In order to reduce the lead to finely divided condition, it is placed in pot 50 and melted and allowed to run through pipe 52 in a fine stream into the body oil liquid in tank 54 and the resulting violent expansion produced by the contact of the melted lead with the liquid, causes mechanical breaking up of the lead into fine particles, which are well adapted for the reactions required in my process.

The finely divided lead is discharged into the first reaction cell 2 and enough water is supplied to said tank to lill the same up to the level of the overflow pipe 30. Then the process is well under way, all of the cells 2, 3 and 4 will be filled up to the level of their overflow pipes and water will be continually furnished from the reservoir 47 to maintain a continual overflow from each cell to the neXt and from the last cell to the settling tank 5 or 6, which for the time being is connected through its valve 36 or 37 to the pipe 33, the other settling tank being at that time cut off from such connection. Atmospheric air is drawn con tinually through inlet 8, ozonizer 1 and outlet 9 and forced through valves 26, 27 and 28 into the lower parts of the respective reaction cells 2, 3 and 4. Such air being ozonized in passing through the ozonizer and producing in each cell an upward current of air bubbles, in which the air is ozonized sufliciently to produce a strong oxidizing effect. The velocity of this upward air current is also'suifrcient to produce a considerable agitating action. Thus in the first reaction cell 2 finely divided lead is subjected to rapid oxidation by agitation thereof in the presence of ozonized air and water. The current of atmospheric air thus caused to passthrough the body of water in Contact with the finely divided lead, contains also a small proportion of carbon dioXid, so that the finely divided lead is subjected to carbonizing action as well as oxidation, with the result that finely divided lead pigment consisting wholly or partially of white lead is formed and rises to the upper part of' the body of water in the cell 2 and overflows with the water through pipe 30` into the cell 3. If desired', an additional amount of carbon dioXid may be supplied to the air for into reaction cell 3 will, in general, be somewhat grayish in color, said material being subjected in reaction cell 3 to further oxidation by the ozonized air supplied through pipe 23, with the result that it overflows through pipe 31 in a much lighter or whiter condition. This operation may be repeated as often as necessary to produce a pure white product. The iinal product overflows through pipe 23 to the settling tank 5 or 6 and is collected therein by settling. Said .tanks are alternately cut off from the supply pipe so as to facilitate settling out of the white lead. The clear overlying liquid may then be drawn off through the pipe 42 or 43 by pump 45 and forced into reservoir 47 from which it flows through the valve 49 to the reaction cell 2.

lWhat I claim is:

l. rlhe process of making lead pigment, which consists in subjecting finely divided lead to agitation in the presence of water and ozonized air.

2. The process of making a lead pigment which consists in passing a current of ozonized atmospheric air upwardly through a body of divided lead immersed in water, in such manner that the ozonized air oXidizes and agitates the lead and carries the resulting finely divided lead compound upwardly out of the body of divided lead.

3. The process of making a pigment containing white lead which consists in subjecting lead to the action of ozone, in the presence of water and carbon dioXid.

4. The process of making a pigment containing white lead, which consists in subjecting lead to the action of atmospheric airy` containingozone and carbon dioxid, in the presence of water.

5. The process of making lead pigment, which consists in agitating a body of divided lead in the presence of water and ozonized air in such a manner as to produce a lead compound, removing such compound from said body of divided lead and subjecting said compound to further action of ozonized air inthe presence of water.

6. The process of making a pigment containing white lead which consists in melting lead, passing a line stream of such melted lead into water to produce finely divided lead having a coating of oXid,.and subjecting such divided lead to the action of ozon ized air, in the presencel of water and carbon dioXid.

in testimony whereof I have hereunto set my hand, at Los Angeles, California, this 24th day of January, 1917.

JAMES E. SEELEY. 

